Marshall CH, et al. - In this retrospective cohort study with 49,143 consecutive patients, researchers examined if cardiorespiratory fitness (CRF) has any impact on lung and colorectal cancer outcomes. Participants had exercise stress testing, were aged from 40 to 70 years, were without cancer, and were treated within the Henry Ford Health System in Detroit, MI. Categories of CRF, which was measured in metabolic equivalents of task, were <6 (reference), 6 to 9, 10 to 11, and ≥12. Via linkage to the cancer registry, they determined incident cancer. In this largest study on this topic, a lower risk of incident lung (77%) and colorectal cancer (61%) was observed in both sexes relative to higher CRF. Also, in those diagnosed with lung or colorectal cancer, higher CRF was related to a lower risk of all-cause mortality.